Adhesive cement products and processes of making same



Patented Aug. 14, 1945 ADHESIVE CEMENT PRODUCTS AND PROC- ESSES OF MAKING SAME Kenneth Findley, Arthur 0.

Becker, and Jesse Matteson,

Krueger, Roy H. Milwaukee, and

Ralph Findley, Elm Grove, Wis., assignors to The F. G.

notation of Wisconsin No Drawing. Application December a, 1942,

Serial No. 467,812

13 Claims.

This invention relates to the production of an adhesive or cement particularly constituted and adapted for use in afiixing. one edge of a label to a can or similar container in a labeling machine.

The invention resides in the nature and properties of the cement or adhesive as a composition of matter and as a final product or article of manufacture and in the process of producing the same.

In labeling machines it is the practice to apply dabs of hot pick-up cement to the can and then so handle the can and the label in the machine that the can automatically picks up the label. Such cement must have the properties of effecting a quick stickor adhesion while possessing a lingering tackiness, and it must be variable as to composition in a predetermined or controlled manner so as to be effective in environments which vary widely as humidity.

In the adhesive manufacturing industry, prior to the present invention, the cement, after it has been compounded, is in such form that it is difllcult and unsatisfactory for the user to handle. After it solidifies it must be broken up at the point of use, and this is true even though it be broken up to some extent before shipment. In any event, the user is left without any convenient way of controlling the exact amount which he adds to the glue pot at any particular time, and chips, flakes or fines of the cement find their way into the glue pot, clogging up the spac between glue rolls and scraper with consequent inadequate amount of cement on roll, and also on to the working areas. Thus time is lost and working and operating conditions are annoying and unsatisfactory.

to temperature and The object of the present invention is to pro-' vide an adhesive of this character in the form of a pellet, tablet, or briquette of predetermined weight, and preferably of uniform size and shape, and of such character that the pellets, tablets or briquettes will not adhere to each other but will remain as self-subsistent, hardsurfaced, solid masses. The user is thus afforded very convenient control over the amount of adhesive or cement which he employs or adds to the glue pot at any particular time. In this form the adhesive or cement is free-flowing from the container in which it is shipped or stored. The pellets may be poured from their containers into the glue pot. Because of their hardness and their hard surface, they will not chip or break nor will they powder with ordinary handling. They are clean to handle, store, and

Findley 00., Milwaukee, Wls., a corstock. They are ready for use as supplied, and

drop of temperature in the glue pot. Further-' more, since the pellets are solid, they will not clog the glue wheel of the glue pot and being small they will melt quickly as they immediately become entirely surrounded with the previously heated cement or adhesive. There is no waste, and it'is convenient to keep a package handy at each machine.

We have discovered that these objects may be accomplished by processing in a certain-special way, materials having special physical and chemical properties.

Generally speaking, the invention proposes to melt together a resin, conveniently rosin or colophony, or some appropriately modified natural or synthetic resin, hydrogenated oil, amorphous wax, paraflln wax, and an antioxidant. This may be accomplished by placing these materials in a steam-jacketed cooker and heating them up to a temperature from 100 C. to 120 C., and stirring them thoroughly while they are heated until they are completely blended. The mixture is then drawn into pans to solidify.

As the temperature decreases, the solubility of the hydrogenated oil, amorphous wax, and paraffin in the resin decreases. has reached room temperature, portions of the materials, which were used in excess of their solubility in resin at room temperature, crystallize out, causing the entire mass to become hard, tough, and crystalline. v

The present invention proposes to form the material in pellets in the manner hereinabove described, but we have found for proper pelleting in a machine it is necessary, among other things, to let the material lie for several days at room temperature to complete crystallization and then cool it to 4 centigrade for several days. Too rapid cooling of the material would prevent the proper crystallization necessary for pelleting operation.

After the material has been cooled and aged, it is in the form of slabs or cakes. These slabs or cakes of the adhesive are then broken up and comminuted or reduced to a small particle size y grinding or pulverizing them in a suitable mill or grinder. The finely divided material is then subjected to aforming and pressing operation which shapes the ground particles into pellets, tablets, or briquettes, of definit or predetermined shape, size, and weight. The pellets are small in size; for example, they may weigh g t to the ounce or one hundred and thirty- When the mass two to'a pound. The shape may be varied. Pellets hithe form of small rectangular blocks, cubes, sp eres, ovals, or the like, may be utilized advantageously. Any suitable briquetting, machine may be employed to accomplish the forming or shaping operation. A self-subsistent, hard-surfacedmass, with the particles of the massbonded therein by adhesion, is thus obtained. The mass has a hard, smooth or glossy surface so that the pellets, briquetteaor tablets. when packaged and subjected to ambient temperatures, will not soften and will not stick or adhere together, but will retain their original form and their original structural properties.

The following tabulation indicates a typical range of compounds which may be employed in practicing the present invention:

Percentage Per- Pep Pen 7 Percenthydrogencentage Boit- Range age ate? oil (tzitre sgiorpara; snag of: 1'- ms p ous po a on to 90 c. w flnwsx oxidant =0. d. 74 15 5 1 60 16-38 74 l3 l0 2 l 66 -49 79. i0 6 6 i 60 18-64 'I'heuseofaresinintheformofrosinor colophony is advantageous because of its low cost and its ready availability. The purpose of the resin, in whatever form it is used, is to furnish adhesiveness to the formulation. The resin employed can be anyone of a number of commercial grades, which consist of the anhydrides of abietic, sapinic, pemaric, etc. acids, or their isomeric forms.

The hydrogenated oil is a hardened oil, or oils, treated with hydrogen in the presence of a catalyst (usually nickel), thereby converting part or all of the glycerids present to stearln with not Over three per cent free fatty acid present calculated as oleic. We used the hydrogenated oil of the above characteristics as we found by experimentation it was necessary to produce a material of suitable hardness and plasticity for both our manufacturing process as well as the customers final satifactory use. The purpou of the hydrogenated oil is to lower'the solidifying temperature to a point where it will remain tacky enough after being applied on the container to complete the function of labeling. This function involves application 'of dots of the cement to the can, with subsequent picking-up of the label by these dots, and ability of the cement to hold a label to a can through the complete cycle of the labeling operation. Any animal or vegetable hydrogenated oil, such as hydrogenated fish oil, hydrogenated cotton seed oil, hydrogenated peanut oil or hydrogenated soy bean oil may be utilized. It does not make any diflerence what oil is hydrogenated, as long as the end product is stearin, the titre between 50 centigrade and 70 centigrade and its solubility in rosin not over seven per cent after standing at 21 centigrade for seven days. We have found that the lower the titre of the hydrogenated oil, the more soluble that oil becomes in rosin. For instance:

n the solubility at 21' centigrade is over seven per cent, the material becomes too plastic to form under pressure and will melt enough to gum up the pellet press. Oils that have been used in the past to give the cement the ability to perform its part of the function of labeling a container would not keep the cement hard enough (after cooling and aging) to form uniform pellets, tablets, or briquettes.

The amorphous wax, or micro-crystalline wax, is obtained from the de-waxing of heavy cylinder oil. It has a tough, ductile, tenacious, compact, homogeneous structure. It will shear without fracture and is very adhesive. It is the purpose of the amorphous wax to give the cement the property of releasing from the forming molds.

' because of the wax-like characteristics imparted to the cement. It retards crystallization of the melted cement when it is cooled (useful in the labeling operation) and so gives a lingering tackiness to the dots of cement when applied to the can.

The parailln wax is .a white, translucent, waxy, tasteless, odorless solid consisting of a mixture of solid hydrocarbons, chiefly of the methane series, obtained from petroleum. The purpose of the paraffin wax is to control the melting point of the cement, and it does this without destroying the hardness which is necessary for forming.

1 Parailln wax also imparts some waxy nature to the cement that helps release it from the forming mold. Both the above mentioned waxes aid in giving the pressed surface of the pellet a hard, smooth, slippery finish, which prevents pellets sticking to each other when in normal temperatures, and packed closely in a large quantity.

For the antioxidants any chemical compound that has ability to retard or prevent the oxidation of the material to which it is added is used.

antioxidants are:- phenyl-alpha-naphthylamine, phenyl-beta-naphthylamine, etc. Those useful in our formulation are of necessity the oil soluble types. The antioxidant keeps the flnal pellet from oxidizing. Without an antioxidizing agent present the formed pellet will generate heat from oxidation, and if packed together the heat generated will become great enough to fuse the pellets together. The oxidation of the material at the surface of the pellet changes the surface from a hard, slippery solid to a loose powder. Pellets made without antioxidant will, after several weeks standing, foam very badly when they are melted, due to the oxidized rosin present. This oxidized rosin also has a much higher melting point, and settles to the bottom of the glue pot, gradually building up quite a deposit.

In our grinding and pelleting operation we trap air in the pellets and so we had to overcome the oxidation problem in order to keep our pellet v shape.

Also, the grinding oi the slabs or cakes of the cement in the grinding mill, and the subsequent pressing and forming thereof in the briqur-tte machine, generates heat; To dissipate and ab..orb this heat the mill and machine are operated in a refrigerated environment, wherein a temperature of 4 centigrade is maintained.

From the foregoing it will be understood that the method which embodies the present invention resides in producing an adhesive of the character described in the form of a pellet, tablet,

or briquette, of predetermined weight, and preferably of uniform size and shape, and that this method comprises melting together a resin, a

' function.

hydrog nated oil, waxes, and an antioxidant, coolin the melted mixture at room temperature, aging the cooled mixture for several days at room temperature, thereafter chilling the solidified mixture after it is aged at room temperature, aging the mixture at the chilling temperature, grinding the aged and cooled material, compressing the ground material into pellets of definite shape, size, and weight, and maintaining the environments in which, the material is ground, compressed or formed atrefrigerated temperatures.

To achieve the objective of the present invention it is further essential that the materials have certain physical and that they be blended in certain proportions. The proportions given, in the tabulation hereinabove set forth, are typical of compounds which are entirely satisfactory to meet current "demands, but it is thought that the invention is not limited to these particular proportions although they are highly advantageous ones. The proportions may be varied depending upon the range of operating temperatures-that is, the range of temperatures of theobjects on which the adhesive is used to fulfil its function in the labeling of a container.

Materials or ingredients must be blended in such proportions that the hydrogenated oil will function to lower the solidifying temperature so that the adhesive will remain tacky after application to the can to complete the labeling The waxes must be blended in such proportions that the amorphous wax gives the cement or adhesive the property of releasing and chemical properties.

cent of a paraflin wax,' and one percent of antioxidant. V Y

4. An adhesive composition comprising seventy-four to seventy-nine per cent rosin, ten to fifteen per cent of hydrogenated oil, the glycerids of which have been converted to stearin, with not over three per cent of fatty acid present, said oil having a titre of between fifty degrees centigrade and seventy degrees centigrade, five to ten per cent of amorphous wax, two to five per cent of parafiin and one per cent of an antioxidant.

5. An adhesive composition comprising seventy-four to seventy-nine per cent resin, ten to fifteen per cent hydrogenated oil, the glycerids of which have been converted to stearin'with-up to three per cent fatty acids only remaining therein, the oil being up to seven per cent soluble in the resin at 21 C., five to ten per cent of an amorphous wax, two to five per cent of a hydrocarbon wax, and up to one per cent of an" anti-oxidant.

6. An adhesive composition comprising seventy-four to seventy-nine per cent of a. resin, ten to fifteen per cent of a hydrogenated oil, the glycerids of which have been converted to stearin with not over three per cent fatty acid present, said oil having a titre of between fifty degrees centigrade and seventy degrees centigrade and being not more than seven per cent soluble in the resin at twenty-one degrees centigrade, the oil functioning to lower the solidifying temperature from the forming moulds, and also aids in retarding crystallization and so imparts a lingering tackiness to the adhesive after application. The paraffin wax must be utilized in such an amount as to discharge its function ofcontrolling the melting point of the cement without impairing the hardness necessary to forming or compressing in the briquet'ting machine. Incidentally, also, it supplements the action of the amorphous wax in imparting a hard, smooth, slippery finish to the pellets. The amount of antioxidant is believed to be of the order stated since its sole functionv is to preclude the generation of heat and consequent softening of the pellet and the powdering of its surface.

The foregoing description is intended in its particulars to be illustrative rather than limiting, the essential features of'the invention being defined in the appended claims.

We claim:

1. An adhesive composition comprising seventy-four to seventy-nine per cent of rosin, ten to fifteen per cent of hydrogenated oil having a titre of from-fifty degrees centigrade to seventy degrees centigrade, five to ten per cent of amorphous wax, two to five per cent of paraffin wax, and one per cent of an antioxidant.

2. An adhesive composition comprising seventy-four to seventy-nine per cent rosin, ten to fifteen per cent of a hydrogenated oil, the oil being less than seven per cent soluble in the rosin, five to ten perv cent of an amorphous wax, two to five percent of paraffin, and not over one per cent of an anti-oxidant.

3. An adhesive compound comprising seventy-four to seventy-nine percent rosin, ten to fifteen percent hydrogenated oil not over seven percent soluble in the rosin at 21C., five to ten percent of an amorphous wax, two to five perof the adhesive to a point where it will remain tacky after application, five to ten per cent of an amorphous wax functioning to retard crystallization and to give the adhesive the property of easy release from a mold, two to five per cent of a parafiin wax functioning to control the melt.- ing point of the adhesive, and one per cent of an antioxidant.

7. The hereindescribed method of producing a pellet adapted when melted to provide an adhesive and when subjected to ambient temperatures to retain its original form and its original properties as a self-subsistent hard mass presenting a smooth, hard surface and comprising melt ing a mixture including seventy-four to seventynine per cent of a resin, ten to fifteen per cent of a hydrogenated oil having a titre of 50 C. to 70 C., five to ten per cent of an amorphous wax, two to five per cent of a hydrocarbon wax, and one per cent of an anti-oxidant, cooling and aging the melted mixture at room temperature, aging the cooled solidified mixture at a refrigerating temperature, grinding the cooled material at a refrigerating temperature, and compressing the ground material at a refrigerating temperature into pellets of definite shape, size, and weight.

8. The hereindescribed method of producing a pellet adapted when melted to provide an adhesive and when subjected to ambient temperatures to retain its original form and its original properties as a self-subsistent hard mass presenting a smooth, hard surface and comprising melting a mixture including seventy-four to seventynine percent of a resin, ten to fifteen per cent of a hydrogenated oil having a titre of 50 C. to 70 C., five to ten per cent of an amorphous wax, two to five percent of the hydrocarbon wax and one per cent of an anti-oxidant, cooling and aging the melted mixture at room temperature, chilling and aging the cooled solidified mixture at a temperature below 5 0., rinding the cooled material, compressing the ground material into pellets of definite shape, size, and weight, and maintaining the environments inwhich the material is ground and compressed at a temperature below C.

'9. The method of producing a pellet adapted when melted to provide an adhesive and when subjected to ambient temperatures to retainits predetermined form and a smooth and hard surface and comprising melting a mixture including seventy-four to seventy-nine per cent 01' a resin, ten to fifteen per cent oi a hydrogenated oil, the oil being less than "1% soluble in the resin, live to ten per cent 01' a wax, and 1 per cent of an anti-oxidant, cooling the melted mixture at room temperature, aging the cooled mixture at room temperature, chilling and aging the cooled, aged mixture at a temperature below 5 C., grinding thechilled mixture at a temperature below 5 C., and compressing the ground material at a temperature below 5 G. into pellets oi predetermined shape, size, and weight.

10. The method of producing a hard and smooth surfaced, pelleted adhesive retaining its predetermined form at ambient temperatures and comprising melting a mixture including seventy-four to seventy-nine per cent of a resin, ten to fifteen per cent of a hydrogenated oil, the oil being not over 7% soluble in the resin at 21 0., five to ten per cent of an amorphous wax, two to flve per cent of a paraflln wax, and one per cent of an anti-oxidant, aging the mixture at room temperature, aging the melted mixture at a temperature of approximately 4 C. and

forming the mixture into pellets at a temperature of approximately 4 C.

11. The method of producing a hard and smooth-suriaced pelleted adhesive unaffected by storage, the method comprising melting a mixture of seventy-four to seventy-nine per cent of a resin, ten to fifteen per cent of a hydrogenated oil having a titre of 50 to 70 C.-, five to tenper cent of an amorphous wax, two to five per cent of a hydrocarbon wax, and one per cent of an not over 5 0.,

anti-oxidant, aging the mixture at room temperature, aging the mixture at a temperature below 15 0., grinding the mixture at a temperature of not over 5 C., and pressing the ground mixture into pellets below the temperature oi 5 C.

12. The method of producing a hard and smooth-surfaced, pelleted adhesive unaffected by storage, the method comprising the steps of melting a mixture or seventy-four to seventy-nine per cent 0! a resin, ten to fifteen per cent of a hydrogenated oil less than seven percent soluble in the resin, five to ten per cent of an amorphous wax, two to five per cent of a hydrocarbon wax, and one per cent 01 an anti-oxidant, cooling and aging the mixture at room temperature in open pans, aging the mixture at a temperature below 5 0., grinding the 'mixture at a temperature of and pressing the ground mixture into pellets below the temperature of 5 C.

13. The method of producing a hard and smooth-surfaced, pelleted adhesive retaining its predetermined form at ambient temperatures and comprising the steps of melting a mixture including seventy-tour to seventy-nine per cent of a resin, ten to fifteen per cent 01' a hydrogenated oil, the glycerids of which have been converted to stearin with no more than three percent oi fatty acids remaining five to ten per cent of an amorphous wax. two to five per cent of a hydrocarbon wax, and one per cent of an anti-oxidant at a temperature from to C., agitating the mixture during melting, aging the mixture at room temperature, aging the mixture at approximately 4 0., grinding the mixture at a temperature of approximately 4 0.. and pelleting the mixture at a temperature of approximately 4? C.

KENNEI'H FINDLEY. ARTHUR C. KRUEGER. ROY H. BECKER. JESSE MA'I'IESON. RALPH FINDLEY. 

